A lot of people are claiming to have the HD trailer/teaser for Harry Potter and the Deathly Hallows, but I have yet to find any copy that’s 480p or better. Cianan sent in this link which provides the trailer in 360p (9.33MB). I’ve also uploaded it to mirror sites just in case: RapidShare and Hotfile.
Given that this isn’t HD, I’m not going to file it under movies, but news instead. Enjoy!